Scaling Testing at Vinted Pay: How we Build Reliability for Millions
Vinted Pay is a big step for our community with an ambitious mission: building an in-house payment platform that makes buying and selling across borders feel even easier, safer, and more supported. We approach this as a new part of Vinted – a chance to shape something important from the ground up, with the backing of a team that believes in moving fast but getting things right.
Our upcoming payment system not only connects buyers and sellers, but does it with stability, speed, and the ability to adapt fast as we grow – qualities at the heart of Vinted engineering. So, join us as we explore how we scale testing at Vinted Pay and what it really takes to deliver reliability for millions with the help of our Lead Test Automation Engineer.
Meet Viktorija
My name's Viktorija, and I've been with Vinted for almost 3 years. As Lead Test Automation Engineer, I spend my days working with talented teams on testing strategy, building frameworks, and digging into the details that help us deliver for our members every single day. For engineers, Vinted Pay is a chance to experiment, collaborate and shape something from a blank page – while knowing your work makes a genuine impact.
Solving technical puzzles at scale
From the start, Vinted Pay has meant taking on fresh challenges. We needed to deliver all the payment features our members use – like card payments, Vinted Balance withdrawals, and verification – while also preparing to migrate millions of members from our previous providers to the new platform. From there, our focus turned to scaling even further: supporting additional users, introducing multiple currencies, and handling large transaction volumes, all without any disruption to the Vinted experience.
For this, "just running the usual tests" wasn't enough. Each step raised new questions: Would this experience scale for everyone who uses Vinted? Would it hold up under pressure? Could our systems recover quickly if something unexpected happened? To answer these, we developed a layered approach using API contract test automation, chaos and performance testing. More on this next!
A team effort, every step of the way
At Vinted Pay, testing is a team sport. Our architecture is built around microservices – so we work closely with SRE, Security, Backend, and Frontend Engineers to ensure everything integrates seamlessly and performs as it should. The frameworks and tools we create often reach far beyond their original scope, supporting more engineering teams than we anticipated, which means more ownership and faster feedback for everyone involved.
Our approach combines lots of methods: multiple layers of test automation, performance and stress tests, and even "what if?" chaos experiments. Ensuring quality is a genuinely collective effort.
Teams collaborate closely – coordinating releases across services, building shared tools, and contributing ideas to sharpen our methods. When we're working on something unfamiliar or tricky, support from other engineers means there's usually someone who's seen a similar challenge before – or is keen to help find a fresh solution.
Learning as we build
Testing at scale means we learn as we go – spotting potential bottlenecks early, making more confident decisions, and building resilience into every part of the process.
Sometimes our work brings unexpected insights: we've used our test results to choose tools, compare programming languages, and refine how we work with data. The main thing that keeps coming up is simple: don't just assume something will work. Take the time to check and use the results to improve. At Vinted, we don't rely on assumptions; we build on evidence.
What you'll find at Vinted Pay
If you're looking for an environment that values hands-on technical growth, open problem-solving, and building something meaningful for our community, Vinted Pay could be the place for you. Here, you'll work with tools like Ruby, JavaScript, TypeScript, k6, Chaos Toolkit, CI/CD pipelines, GO, Kubernetes, AWS, Elasticsearch, Temporal, Grafana, Kibana, Datadog, Clean-Swift, Kotlin, Appium, ES6+, SCSS, HTML5, Playwright, and Postman – with the room to shape our engineering approach alongside skilled colleagues, all while making an impact beyond the code.
Your next step?
Vinted Pay is growing, and so are the possibilities. We're still early in the journey, but every challenge brings us closer to a payments system that’s ready for the future of second-hand. Want to help us build it? We'd be glad to hear from you.